1. Technical Field
This invention relates to keyboards and keyboard instruments such as pianos.
2. Background Art
For example, Japanese Patent Application Laid-Open Publication No. 2002-258835 discloses a keyboard instrument having a structure with a plurality of keys respectively including a wippen that rotates when a key is depressed, a jack that is driven by the wippen swinging, and a hammer that strikes a string after being driven by the jack.
This type of keyboard instrument includes a wippen rail and a hammer rail respectively running the entire length of the plurality of keys in the array direction of the plurality of keys.
A plurality of wippen flanges that corresponds to respective keys are attached to the wippen rail, and a plurality of wippens are respectively attached to the wippen flanges by pins such that the wippens can swing.
A plurality of hammer flanges are respectively attached to the plurality of wippens on the hammer rail. Respective hammer shanks of the plurality of hammers are attached to the hammer flanges with pins such that the hammer shanks can swing.
This type of keyboard instruments needs the wippen to be individually attached to the wippen flange with a pin. Therefore, when the plurality of wippens are being attached to the wippen rail, the plurality of wippens need to be individually attached to the wippen rail one after another according to the attaching procedure for attaching a plurality of wippens. This results in problems such as the assembly process being tedious, productivity being low, and the cost being high.
Furthermore, the hammer of this keyboard instrument needs to be individually attached to the hammer flanges with a pin. Therefore, when a plurality of hammers are being attached to the hammer rail, the plurality of hammer flanges need to be individually attached to the hammer rail one after another. This result in problems such as the assembly process being tedious, productivity being low, and the cost being high.
In addition, recently, applying this type of action that adds a more realistic key touch to electronic keyboard instruments that produce a hammer struck string sound using an electronic sound source circuit is being proposed.
In ordinary electronic keyboard instruments, a switch is provided under each key to detect the depressing and releasing of keys, or the velocity of the key depressing. However, if this type of action is included in such electronic keyboard instruments, a new problem emerges.
That is, the switch provided for each key is a component that receives the most mechanical load when the keys are used, and malfunctions often. As a result, the switch needs frequent repair and replacement. Conventionally, the keys could have been repaired or replaced relatively easily by removing the keys or the like, but if the keyboard has the above-mentioned type of mechanism, repairing and replacing keys becomes more difficult.
In addition, recently, applying this type of action that adds a more realistic key touch to electronic keyboard instruments that produces the hammer struck string sound using an electronic sound source circuit is being proposed. In this case, the usage of resins or the like that has a material property that is lighter and allows higher productivity than regular cast metal is proposed as the material of the bracket, which is a supporting member that supports the hammer and the wippen.
However, the bracket supports the entire action mechanism, and therefore a bracket using resin or the like had insufficient strength compared to conventional brackets made of cast metal.
Furthermore, the keyboard is structured such that the supporting member such as a bracket is supported by a plurality of long rails, and therefore, even if a material that is light and high in productivity such as resin is used, the supporting member such as a bracket can maintain sufficient strength.